Threaded screw fastener characterized by high pull-out resistance, reduced installation torque, and unique head structure and drive socket implement or tool therefor

ABSTRACT

A threaded screw fastener is provided with thread structure wherein each thread of the threaded screw fastener comprises rearward and forward flank surfaces which effectively serve to enhance the pull-out resistance characteristics or properties of the threaded screw fastener while reducing the installation or insertion torque characteristics or properties of the threaded screw fastener. In addition, the forward and rearward flank surfaces of adjacent threads are separated from each other a predetermined amount so as to effectively capture overlapped edge portions of adjacent roofing panels in order to prevent backing out of the threaded screw fasteners even when the roofing panels undergo expansion and contraction as a result of being exposed to cyclically varying environmental or weather conditions.

CROSS REFERENCE TO RELATED PATENT APPLICATION

This patent application is a Continuation-in-Part (CIP) patentapplication of U.S. patent application Ser. No. 10/681,193 which wasfiled on Oct. 9, 2003.

FIELD OF THE INVENTION

The present invention relates generally to threaded screw fasteners, andmore particularly to a new and improved threaded screw fastener whichhas unique and novel buttress thread structure which effectivelyprovides the new and improved threaded screw fastener with reducedinstallation or insertion torque characteristics, and which alsoeffectively provides the new and improved threaded screw fastener withenhanced pull-out resistance characteristics, whereby the new andimproved threaded screw fastener can be easily and readily inserted orinstalled, and retained, within various different substrates, such as,for example, steel, concrete, aluminum, wood, and thermoplasticmaterials. Still further, the new and improved threaded screw fastenerhas unique and novel head structure which not only enables the new andimproved threaded screw fastener to be inserted or installed within asubstrate as a result of being capable of being alternatively utilizedeither with a Phillips head drive socket implement or tool, or with ahexagonal drive socket implement or tool, but in addition, the headstructure comprises low-profile domed structure such that when the newand improved threaded screw fastener is utilized to secure waterproof orenvironmental membranes upon roof decking assemblies, the new andimproved head structure will not present any raised edge or sharplypointed corner structure which would otherwise tend to cut or pierce thewaterproof or environmental membranes whereby the structural integrityof the waterproof or environmental membranes would be adversely affectedas a result of propagated tearing or shredding of the same, particularlyunder high-wind, uplifting force conditions. A last embodiment of thethreaded screw fastener also incorporates specific structure which notonly enables its usage in connection with the seaming together ofoverlapped edge portions of adjacent roofing panels, but in additionenhances the back-out resistance of the threaded screw fasteners withrespect to the roofing panels.

BACKGROUND OF THE INVENTION

When a threaded screw fastener is to be inserted or installed within aparticular substrate, the threaded screw fastener must obviously berotated in order to enable the threaded screw fastener to threadedlyengage the substrate material. Accordingly, a rotational drive forcemust be imparted to the threaded screw fastener. Conventionally, the twomost common means for imparting rotational drive forces to threadedscrew fasteners is either by means of a hexagonal drive socket implementor tool which is adapted to engage a corresponding hexagonallyconfigured head portion of the fastener, or alternatively, by means of aPhillips head drive socket implement or tool which is adapted to engagea correspondingly configured Phillips head portion of the fastener.Typical threaded screw fasteners, respectively having such a hexagonallyconfigured head portion, or a Phillips head portion, are disclosedwithin FIGS. 1 and 2. More particularly, a first conventional PRIOR ARTthreaded fastener is disclosed within FIG. 1 and is generally indicatedby the reference character 10.

The threaded fastener 10 is seen to comprise a threaded shank portion12, and a head portion 14. The head portion 14 has a hexagonalcross-sectional configuration, and it is also seen that thehexagonally-configured head portion 14 has a constant depth dimension D,as defined between vertically spaced, horizontally disposed, upper andlower planar surfaces 16,18. As a result of such structure, thehexagonally-configured head portion 14 exhibits a relatively largeprofile. Alternatively, a second conventional PRIOR ART threadedfastener is disclosed within FIG. 2 and is generally indicated by thereference character 110. The threaded fastener 110 is seen to comprise asimilarly threaded shank portion 112, and a head portion 114. The headportion 114 is provided with a substantially X-shaped slotted region 116which is recessed within the head portion 114 so as to be capable ofaccommodating a Phillips head drive socket implement or tool, and it isadditionally seen that the upper surface 118 of the head portion 114 hasa substantially domed configuration which circumferentially slopesdownwardly so as to terminate in a relatively thin-dimensionedperipheral surface 120.

While the conventional PRIOR ART threaded fasteners 10,110 normallyexhibit satisfactory operational or performance characteristics, theconventional PRIOR ART threaded fasteners 10,110 do in fact exhibit somesignificant operational drawbacks. For example, different fieldpersonnel usually prefer to use a particular one of the two differenttypes of conventional PRIOR ART threaded screw fasteners, andaccordingly have suitable drive socket implements or tools for drivinglyengaging the head portions of the particular threaded screw fasteners.The obvious problem with the existence or availability of the twodifferent types of conventional PRIOR ART threaded screw fastenersresides in the manufacture and distribution of such threaded screwfasteners, that is, the threaded screw fastener manufacturers need tomanufacture or fabricate the two different types of threaded screwfasteners, they need to stock the two different types of threaded screwfasteners in their available inventories, and they need to maintainproper and appropriate records in connection with the distribution ofsuch different types of threaded screw fasteners to differentdistribution centers or end-use customers. Similar manufacturing,fabrication, inventory, distribution, and logistical problemscorrespondingly exist in connection with the availability of thesuitable drive socket implements or tools for drivingly engaging thehead portions of the different threaded screw fasteners. A needtherefore exists in the art for a new and improved threaded screwfastener which is provided with a head portion that has integrallyincorporated therein both hexagonal and Phillips head structure so as tobe capable of being rotationally driven by means of a new and improvedsingle drive socket implement or tool which likewise has integrallyincorporated therein structure which is uniquely adapted to engageeither one of the hexagonal and Phillips head structures integrallydisposed upon the head portion of the threaded screw fastener.

In addition, it is seen that the vertically spaced, horizontallydisposed, upper and lower planar surfaces 16,18, together with the six,vertically oriented side surfaces or facets 20 of the head portion 14,define a plurality of vertically spaced, upper and lower peripheral edgeportions 22, wherein each one of the upper and lower peripheral edgeportions 22 defines, includes, or comprises a 90° angle. It is also seenthat adjacent pairs of the side surfaces or facets 20,20 define aplurality of vertically oriented edge regions or loci 24 therebetween,whereby the upper and lower termini of the vertically oriented edgeregions or loci 24 define sharply pointed corner loci 26. Accordingly,when the threaded screw fasteners 10 are utilized, for example, inconnection with the fastening or securing of waterproof or environmentalmembranes to underlying roof decking assemblies, the peripheral edgeportions 22, defined between the vertically oriented side surfaces orfacets 20 and the upper planar surface 16, as well as the upper cornerloci 26 disposed within the plane of the upper planar surface 16,present sharply configured structures.

It has been found that such sharply configured structures caneffectively cut or pierce the waterproof or environmental membraneswhen, for example, the waterproof or environmental membranes are forcedinto contact with the fastener head portions 14 as a result of, forexample, workmen walking upon the upper surface portion of the roofdecking assembly. Accordingly, once the waterproof or environmentalmembranes are cut or pierced, the waterproof or environmental membranestend to undergo further structural deterioration, such as, for example,propagated shredding or tearing, particularly under high-wind lift forceconditions, thereby effectively compromising the structural integrity ofthe waterproof or environmental membranes and of course the protectiveproperties of the waterproof or environmental membranes with respect tothe underlying roof decking and insulation substrates. This is obviouslynot a desirable situation from the viewpoint of installing a proper,environmentally protected roof decking system. A need therefore existsin the art for a new and improved threaded screw fastener which isprovided with a head portion that not only has integrally incorporatedtherein both hexagonal and Phillips head structure so as to be capableof being rotationally driven by means of a single drive socket implementor tool which likewise has integrally incorporated therein structurewhich is uniquely adapted to engage either one of the hexagonal andPhillips head structures integrally disposed upon the head portion ofthe screw fastener, but in addition exhibits a relatively low profile.

Continuing further, and with reference now being made to FIGS. 3 and 4,an additional conventional PRIOR ART threaded screw fastener ispartially disclosed and is generally indicated by the referencecharacter 210. The threaded screw fastener 210 comprises a shank portion212 upon which a plurality of buttress-type threads 214 are formed. Ascan best be seen or appreciated from FIG. 4, each one of theconventional buttress-type threads 214 is seen to comprise a slightlyinclined rearward flank surface 216 and a significantly inclined forwardflank surface 218, a predetermined thread pitch P, as measured betweenthe same points of successive thread crest portions 220, and apredetermined spacing S as determined between the root region of therearward flank surface 216 of a particular thread and the root region ofthe forward flank surface 218 of the next or successive thread.

As is well-known in the art or industry, the rear flank surface 216, aswell as the pitch P, play critical roles in, or effectively determine,the pull-out resistance characteristics or properties of the fastener210, while the forward flank surface 218, and the spacing S, likewiseplay critical roles in, or effectively determine, the installation orinsertion torque characteristics or properties of the fastener 210. Asis further well-known in the art of industry, the ideal or perfectlydesigned fastener will exhibit relatively high pull-out resistancecharacteristics or properties, while concomitantly exhibiting relativelylow installation or insertion torque characteristics or properties.Unfortunately, conventional or PRIOR ART fasteners, such as, forexample, the fastener 210, as disclosed within FIGS. 3 and 4 andcharacterized by means of the conventional or PRIOR ART buttress threadstructure, cannot effectively simultaneously achieve the aforenotedrelatively high pull-out resistance characteristics or properties andthe relatively low insertion or installation torque characteristics orproperties.

More particularly, in order to effectively increase the pull-outresistance characteristics or properties of the threaded screw fastener210, the diametrical extent of the threaded screw fastener 210 wouldhave to be increased, that is, the external diametrical dimensions orextents of both the shank portion 212 and the threads 214 as determinedby means of the crest portions 220 thereof. Increasing the diametricaldimension or extent of the threaded screw fastener 210, however, is notdesirable or viable for several reasons. Firstly, for example,increasing the diametrical dimension or extent of the threaded screwfastener 210 obviously increases the amount of material that is requiredto be structurally incorporated within each fastener 210, and thereforethe manufacturing or fabrication costs per fastener are correspondinglyincreased. In addition, or secondly, increasing the diametricaldimension or extent of the threaded screw fastener 210 also serves toincrease the installation or insertion torque characteristics orproperties of the fastener 210, which, of course, is precisely theopposite objective that is sought to be achieved in connection with thethreaded screw fastener 210. Viewed from an opposite point of view, if,for example, the diametrical dimension or extent of the threaded screwfastener 210 was decreased so as to effectively reduce the torqueinstallation or insertion characteristics or properties of the threadedscrew fastener 210, then the pull-out resistance characteristics orproperties of the threaded screw fastener 210 would be correspondinglyreduced, which, again, is precisely the opposite objective that issought to be achieved in connection with the threaded screw fastener210. A need therefore exists in the art for a new and improved threadedscrew fastener which can simultaneously achieve both enhanced pull-outresistance characteristics or properties, and reduced installation orinsertion torque characteristics or properties, while also retainingmanufacturing or fabrication costs at a viable or cost-effective level.

Continuing still further, and in connection with, for example, thesecuring together of overlapped edge portions of adjacent roofingpanels, threaded screw fasteners are inserted through the overlappededge portions of adjacent roofing panels, and rubber washers, or thelike, are also disposed beneath the head portions of the fasteners so asto effectively seal the fastener sites against the penetration of water.As is well known, however, roofing systems are subjected toenvironmental conditions which cause the roofing panels to undergoexpansion and contraction, and as a result of such expansion andcontraction of the roofing panels, forces are impressed upon thethreaded fasteners which cause them to become loose and back out fromtheir fastened states or positions within the overlapped edge portionsof the adjacent roofing panels. Accordingly, the rubber washers, or thelike, will no longer be engaged with the overlapped edge portions ofadjacent roofing panels whereby the fastener sites will no longer beproperly sealed or protected against water penetration. A need thereforeexists in the art for a new and improved threaded fastener which isspecifically structured for securely fastening together the overlappededge portions of adjacent roofing panels, and wherein further, thethreaded fasteners will not exhibit back-out from their fastener siteseven when the roofing panels are repeatedly or cyclically subjected torelatively hot and cold environmental conditions which would cause theroofing panels to undergo or experience expansion and contraction.

SUMMARY OF THE INVENTION

The foregoing and other objectives are achieved in accordance with theteachings and principles of the present invention through the provisionof a new and improved threaded screw fastener which comprises a headportion that has low profile domed structure integrally incorporatedtherein, and wherein further, the head portion also has unique and novelcombination structure which permits the threaded screw fastener to berotatably driven either by means of a rotary drive tool having, forexample, hexagonally configured drive structure integrally incorporatedtherein, or alternatively by means of a rotary drive tool having, forexample, Phillips head drive structure integrally incorporated therein.In this manner, the threaded screw fastener, having such combinationhead structure, can be drivingly inserted or installed within substratesregardless of the particular drive socket implement or tool beingutilized by field installation or job site personnel. Furthermore, inaccordance with additional teachings and principles of the presentinvention, there is provided a new and improved drive socket implementor tool which has integrally incorporated therein both hexagonallyconfigured drive structure, Phillips head drive structure, and domedcontour structure for not only structurally accommodating both thehexagonally configured structure and the Phillips head structureintegrally incorporated upon the head portion of the threaded screwfastener, but in addition, for accommodating the low profile domedstructure of the head portion of the threaded screw fastener. Lastly,the threaded screw fastener also comprises thread structure wherein eachthread of the threaded screw fastener comprises unique and novelrearward and forward flank surfaces which effectively serve tosimultaneously enhance the pull-out resistance characteristics orproperties of the threaded screw fastener while reducing theinstallation or insertion torque characteristics or properties of thethreaded screw fastener. More particularly, in connection with theseaming together of overlapped edge portions of adjacent roofing panels,the threaded screw fasteners incorporate specific crest height, threadpitch, and rear and front face or flank structure which effectivelyenable the overlapped edge portions of adjacent roofing panels toeffectively be trapped between successive threads of the fasteners so asto enhance the back-out resistance of the fasteners with respect to theroofing panels, even when the roofing panels experience expansion andcontraction as a result of varying environmental or temperatureconditions.

BRIEF DESCRIPTION OF THE DRAWINGS

Various other objects, features, and attendant advantages of the presentinvention will be more fully appreciated from the following detaileddescription when considered in connection with the accompanying drawingsin which like reference characters designate like or corresponding partsthroughout the several views, and wherein:

FIG. 1 is a perspective view of a conventional, PRIOR ART threaded screwfastener wherein the head portion integrally formed thereon has ahexagonal cross-sectional configuration;

FIG. 2 is a perspective view of a conventional, PRIOR ART threaded screwfastener wherein the head portion integrally formed thereon has Phillipshead drive structure formed therewithin;

FIG. 3 is a partial side elevational view of a conventional, PRIOR ARTthreaded screw fastener which is provided with standard buttressthreads;

FIG. 4 is an enlarged partial cross-sectional view of the conventional,PRIOR ART threaded screw fastener, as disclosed within FIG. 3, showingthe detailed structure of several of the individual threads of thethreaded screw fastener, particularly the rearward and forward flanksurfaces thereof;

FIG. 5 is a perspective view, similar to those of FIGS. 1 and 2,showing, however, a first embodiment of a new and improved threadedscrew fastener constructed in accordance with the principles andteachings of the present invention wherein the head portion of thethreaded screw fastener is integrally provided with combinationstructure which will permit the threaded screw fastener to be rotatablydriven either by means of, for example, a hexagonally configured drivesocket implement or tool, or alternatively, by means of, for example, aPhillips head drive socket implement or tool;

FIG. 6 is a perspective view, similar to that of FIG. 5, showing,however, a second embodiment of a new and improved threaded screwfastener constructed in accordance with the principles and teachings ofthe present invention wherein the head portion of the threaded screwfastener is likewise integrally provided with combination structurewhich will permit the threaded screw fastener to be rotatably driveneither by means of, for example, a hexagonally configured drive socketimplement or tool, or alternatively, by means of, for example, aPhillips head drive socket implement or tool;

FIG. 7 is a perspective view, similar to those of FIGS. 5 and 6,showing, however, a third embodiment of a new and improved threadedscrew fastener constructed in accordance with the principles andteachings of the present invention wherein the head portion of thethreaded screw fastener is also integrally provided with combinationstructure which will permit the threaded screw fastener to be rotatablydriven either by means of, for example, a hexagonally configured drivesocket implement or tool, or alternatively, by means of, for example, aPhillips head drive socket implement or tool;

FIG. 8 is a perspective view of a new and improved drive socketimplement or tool which has been constructed in accordance with theprinciples and teachings of the present invention and which hascombination drive structure integrally incorporated therein whichcomprises hexagonally configured drive structure and Phillips head drivestructure, as well as contoured mating surface structure, foraccommodating and drivingly interfacing with, for example, the headportion of the first embodiment threaded screw fastener as disclosedwithin FIG. 5;

FIG. 9 is a cross-sectional view of the new and improved drive socketimplement or tool, as disclosed within FIG. 8, and as operationallymated or engaged with the head portion of, for example, the firstembodiment threaded screw fastener as disclosed within FIG. 5 so as todefine therewith a drive socket implement or tool-fastener assembly;

FIG. 10 is a partial side elevational view, similar to that of FIG. 3,showing, however, a fourth embodiment of a threaded screw fastenerwherein the thread portion thereof has been constructed in accordancewith the teachings and principles and teachings of the present inventionin order to simultaneously achieve high pull-out resistancecharacteristics or properties, and low installation or insertion torquecharacteristics or properties;

FIG. 11 is an enlarged partial cross-sectional view, similar to that ofFIG. 4, showing, however, the detailed structure of several of theindividual threads of the fourth embodiment threaded screw fastener asdisclosed within FIG. 10, particularly the rearward and forward flanksurfaces thereof, the thread pitch, and the axial spacing definedbetween the root portion of the rearward flank surface of a particularthread and the roof portion of the forward flank surface of the nextsuccessive thread;

FIG. 12 is a side elevational view, partially in cross-section, of afifth embodiment of a new and improved threaded screw fastener which hasincorporated thereon a new and improved screw thread that has beenspecifically constructed in accordance with the principles and teachingsof the present invention so as to permit the new and improved threadedscrew fastener to be used in connection with the securing together ofoverlapped edge portions of adjacent roofing panels wherein the new andimproved threaded screw fasteners will not experience back-out even whenthe roofing panels undergo expansion and contraction under varyingweather and temperature conditions;

FIG. 13 is an enlarged detailed view of the new and improved screwthread that has been incorporated upon the fifth embodiment of the newand improved threaded screw fastener, as illustrated within FIG. 12,such that the fastener will not experience back-out with respect to theroofing panels and will preserve the sealing integrity of the fastenersites; and

FIG. 14 is an enlarged detailed view, similar to that of FIG. 13,showing, however, a sixth embodiment of a new and improved threadedscrew fastener having a modified thread form, with respect to the threadform disclosed within FIG. 13, which may also be incorporated upon thenew and improved threaded screw fastener as illustrated within FIG. 12for use in connection with the securing together of overlapped edgeportions of adjacent roofing panels.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring again to the drawings, and more particularly to FIG. 5thereof, a first embodiment of a new and improved threaded screwfastener, constructed in accordance with the principles and teachings ofthe present invention, is disclosed and is generally indicated by thereference character 310. It is to be noted that, in view of the factthat the first embodiment of the new and improved threaded screwfastener 310 of the present invention has incorporated thereinstructural features which are somewhat similar to those structuralfeatures characteristic of the conventional PRIOR ART threaded screwfasteners 10,110 as respectively disclosed within FIGS. 1 and 2, suchstructural features of the first embodiment threaded screw fastener 310will be designated by similar or corresponding reference charactersexcept that they will be within the 300 series. Accordingly, the new andimproved first embodiment threaded screw fastener 310 is seen tocomprise a threaded shank portion 312, and a head portion 314, whereinthe head portion 314 has integrally formed thereon a first embodiment ofcombination structure which permits the head portion 314 to bealternatively engaged either by means of a hexagonally configured drivesocket implement or tool, or by means of a Phillips head drive socketimplement or tool, whereby rotary drive can be imparted to the firstembodiment threaded screw fastener 310 so as to drivingly install orinsert the first embodiment threaded screw fastener 310 into asubstrate. More particularly, it is seen that the head portion 314 ofthe first embodiment threaded screw fastener 310 comprises a circularwasher member 313 integrally formed upon the upper end of the threadedshank portion 312, and upstanding, combination fastener drive structureis disposed atop the circular washer member 313 such that the circularwasher member 313 effectively forms an annular flanged or shoulderportion surrounding the upstanding, combination fastener drivestructure.

The upstanding, combination fastener drive structure is seen to comprisea centrally located drive member 318 which comprises six vertically oraxially oriented external sides or facets 320 such that the drive member318 has a substantially hexagonal cross-sectional configuration, and asubstantially X-shaped recessed section 328 is internally formed at anaxially central location within the hexagonally configured drive member318 so as to define a Phillips head drive member. It is further notedthat the upper surface portion 316 of the centrally located hexagonallyconfigured drive member 318, which is disposed substantiallytransversely or perpendicular to the longitudinal axis of the threadedscrew fastener 310, actually has a domed configuration such that theupper surface portion 316 slopes downwardly in a circumferential mannerfrom the axially located substantially X-shaped recessed section 328toward the six vertically or axially oriented external sides or facets320 which effectively form the outer periphery of the hexagonallyconfigured drive member 318. In this manner, the vertical heightdimension of the hexagonally configured drive member 318, as defined bymeans of the axial extent of the six vertically or axially orientedexternal sides or facets 320 of the hexagonally configured drive member318, is relatively small.

In addition, due to the circumferentially extending, downwardly slopedcontour of the upper surface portion 316 of the hexagonally configureddrive member 318, the upper edge portions 322 of the six vertically oraxially oriented external sides or facets 320 of the hexagonallyconfigured drive member 318, which substantially correspond to the upperedge portions 22 of the sides or facets 20 of the threaded screwfastener 10 as disclosed within FIG. 1, are not disposed at theuppermost elevational level of the threaded screw fastener 310.Furthermore, since the upper surface portion 316 of the hex-agonallyconfigured drive member 318 slopes downwardly in the aforenotedcircumferential manner, the upper edge regions 322 of the hexagonallyconfigured drive member 318, as defined at the junctions of the uppersurface portion 316 and each one of the external sides or facets 320 ofthe hexagonally con-figured drive member 318, do not comprise 90°angles. Still further, and again due to the circumferentially extending,downwardly sloped contour of the upper surface portion 316 of thehexagonally configured drive member 318, the upper corner regions 326,as defined at the junctions of the vertically oriented edge regions orloci 324 and the upper edge regions 322 of the hexagonally configureddrive member 318, are likewise disposed at an elevational level which isbeneath the uppermost elevational level of the threaded screw fastener310.

Accordingly, if portions of the waterproof or environmental membraneshappen to be effectively forced into contact with the head portions 314of the threaded screw fasteners 310 that secure the waterproof orenvironmental membranes to the underlying roof decking assembly, as aresult of, for example, workmen personnel walking upon the upper surfaceportion of the roof decking assembly, then the waterproof orenvironmental membranes will be forced primarily into contact with andthereby encounter the circumferentially extending, downwardly slopedupper surface portions 316 of the threaded screw fasteners 310, and willnot be primarily forced into contact with or encounter the upper edgeportions 322 of the six vertically or axially oriented external sides orfacets of the hexagonally configured drive member 318. Therefore,cutting, piercing, and ultimate shredding or tearing of the waterproofor environmental membranes is effectively prevented.

Still further, it is also to be appreciated that by means of providingthe first embodiment threaded screw fastener 310 with the combinationfastener drive structure 318, 328 that permits the first embodimentthreaded screw fastener 310 to be rotatably driven by means ofalternative drive socket implements or tools, such as, for example,hexagonally configured socket implements or tools, or by means ofPhillips head configured socket implements or tools, only a single typeof threaded screw fastener 310 is needed at field installation or jobsite locations. This is because the single type of threaded screwfastener 310 can be inserted or installled within a substrate regardlessof the type of drive socket implement or tool that a particular workmanor field personnel may be using at the field installation or job site.

With reference now being made to FIG. 6, a second embodiment of a newand improved threaded screw fastener, constructed in accordance with theprinciples and teachings of the present invention so as to befunctionally similar to the first embodiment of the new and improvedthreaded screw fastener 310 as disclosed within FIG. 5, is disclosed andis generally indicated by the reference character 410. It is to be notedthat in view of the fact that the second embodiment threaded screwfastener 410 is structurally similar to the first embodiment threadedscrew fastener 310, a detailed description of the same, except for thosestructural features unique to the second embodiment threaded screwfastener 410, will be omitted for brevity purposes. It is additionallynoted that those structural features characteristic of the secondembodiment threaded screw fastener 410, that correspond to similarstructural features characteristic of the first embodiment threadedscrew fastener 310, will be designated by similar or correspondingreference characters except that the reference characters will be withinthe 400 series. Accordingly, it is seen, for example, that the new andimproved second embodiment threaded screw fastener 410 is seen tocomprise a threaded shank portion 412, and a head portion 414, whereinthe head portion 414 has integrally formed thereon a second embodimentof combination structure which permits the head portion 414 to bealternatively engaged either by means of a hexagonally configured drivesocket implement or tool, or by means of a Phillips head drive socketimplement or tool, whereby rotary drive can be imparted to the secondembodiment threaded screw fastener 410 so as to drivingly install orinsert the second embodiment threaded screw fastener 410 into asubstrate. More particularly, the head portion 414 of the secondembodiment threaded screw fastener 410 comprises an upper surfaceportion 416 having a domed configuration which slopes downwardly in acircumferential manner from an axially central region of the headportion 414 toward the peripheral region of the head portion 414 aseffectively defined by means of an underlying washer member 413. Inaddition, in a manner similar to that of the first embodiment threadedscrew fastener 310, the combination fastener drive structure of thesecond embodiment threaded screw fastener 410 is seen to comprisesubstantially X-shaped recessed structure 428 which is defined withinthe axially central region of the head portion 414 so as to effectivelydefine a Phillips head drive member, and six vertically or axiallyoriented external sides or facets 420 which are formed upon the externalperiphery of the washer member 413 whereby the external periphery of thehead portion 414 effectively defines a drive member 418 which has asubstantially hexagonal cross-sectional configuration. As a result ofthe aforenoted structure, as facilitated by means of the domed uppersurface portion 416, the vertical height dimension of the hexagonallyconfigured drive member 418, as defined by means of the axial extent ofthe six vertically or axially oriented external sides or facets 420 ofthe hexagonally configured drive member 418, is relatively small.

Still further, due to the circumferentially extending, downwardly slopedcontour of the upper surface portion 416 of the hexagonally configureddrive member 418, the upper edge portions 422 of the six vertically oraxially oriented external sides or facets 420 of the hexagonallyconfigured drive member 418, which substantially correspond to the upperedge portions 322 of the sides or facets 320 of the threaded screwfastener 310 as disclosed within FIG. 5, are not disposed at theuppermost elevational level of the threaded screw fastener 410.Furthermore, since the upper surface portion 416 of the hexagonallyconfigured drive member 418 slopes downwardly in the aforenotedcircumferential manner, the upper edge regions 422 of the hexagonallyconfigured drive member 418, as defined at the junctions of the uppersurface portion 416 and each one of the external sides or facets 420 ofthe hexagonally con-figured drive member 418, do not comprise 90°angles. Lastly, it is also seen that the individual vertically oraxially oriented external sides or facets 420 of the hexagonallyconfigured drive member 418 do not abut each other in a circumferentialmanner but, to the contrary, are effectively separated from each otherby means of arcuate portions 430 of the washer member 413. Accordingly,such structure, in combination with the circumferentially extending,downwardly sloped contour of the upper surface portion 416 of thehexagonally configured drive member 418, effectively eliminates anysharply cornered or sharply edged regions upon the head portion 414 ofthe threaded screw fastener 410.

In light of the foregoing, it can be readily appreciated that ifportions of the waterproof or environmental membranes happen to beeffectively forced into contact with the head portions 414 of thethreaded screw fasteners 410 that secure the waterproof or environmentalmembranes to the underlying roof decking assembly, as a result of, forexample, workmen personnel walking upon the upper surface portion of theroof decking assembly, then the waterproof or environmental membraneswill be forced into contact with and thereby encounter thecircumferentially extending, downwardly sloped upper surface portions416 of the threaded screw fasteners 410. In addition, since the sharp90° edge portions, as defined between the upper edge portions 422 of thesix vertically or axially oriented external sides or facets 420 of thehexagonally configured drive member 418 and the upper surface portion416 of the head portion 414, have effectively been eliminated, as havethe upper sharply pointed corner regions as defined between adjacentones of the six vertically or axially oriented external sides or facets420 of the hexagonally configured drive member 418 and the upper surfaceportion 416 of the head portion 414, then it follows that cutting,piercing, and ultimate shredding or tearing of the waterproof orenvironmental membranes is also effectively prevented.

Still further, it is also to be appreciated, as was the case with thefirst embodiment threaded screw fastener 310, that by providing thesecond embodiment threaded screw fastener 410 with the combinationfastener drive structure 418,428 that permits the second embodimentthreaded screw fastener 410 to be rotatably driven by means ofalternative drive socket implements or tools, such as, for example,hexagonally configured socket implements or tools, or by means ofPhil-lips head configured socket implements or tools, only a single typeof threaded screw fastener 410 is needed at field installation or jobsite locations. Again, this is because the single type of threaded screwfastener 410 can be inserted or installed within a substrate regardlessof the type of drive socket implement or tool that a particular workmanor field personnel may be using at the field installation or job site.

With reference now being made to FIG. 7, a third embodiment of a new andimproved threaded screw fastener, also constructed in accordance withthe principles and teachings of the present invention so as to befunctionally similar to the first and second embodiments of the new andimproved threaded screw fasteners 310,410 as disclosed within FIGS. 5and 6, is disclosed and is generally indicated by the referencecharacter 510. It is to be noted that in view of the fact that the thirdembodiment threaded screw fastener 510 is structurally similar to thefirst and second embodiment threaded screw fasteners 310,410, a detaileddescription of the same, except for those structural features unique tothe second embodiment threaded screw fastener 510, will be omitted forbrevity purposes. It is additionally noted that those structuralfeatures characteristic of the third embodiment threaded screw fastener510, that correspond to similar structural features characteristic ofthe first and second embodiment threaded screw fasteners 310,410, willbe designated by similar or corresponding reference characters exceptthat the reference characters will be within the 500 series.

Accordingly, it is seen, for example, that the new and improved thirdembodiment threaded screw fastener 510 is seen to comprise a threadedshank portion 512, and a head portion 514, wherein the head portion 514has integrally formed thereon a third embodiment of combinationstructure which permits the head portion 514 to be alternatively engagedeither by means of a hexagonally configured drive socket implement ortool, or by means of a Phillips head drive socket implement or tool,whereby rotary drive can be imparted to the third embodiment threadedscrew fastener 510 so as to drivingly install or insert the thirdembodiment threaded screw fastener 510 into a substrate.

More particularly, it is seen that the head portion 514 of the thirdembodiment threaded screw fastener 510 effectively comprises hybridstructure with respect to the structure comprising the head portions314,414 of the first and second embodiment threaded screw fasteners310,410. For example, it is seen that the head portion 514 of the thirdembodiment threaded screw fastener 510 comprises a circular washermember 513 which is integrally formed upon the upper end of the threadedshank portion 512, and upstanding, combination fastener drive structureis disposed atop the circular washer member 513 such that the circularwasher member 513 effectively forms an annular flanged portion whichsurrounds the upstanding, combination fastener drive structure. Theupstanding, combination fastener drive structure is seen to comprise afirst drive member 518 which comprises six vertically or axiallyoriented external sides or facets 520 such that the first drive member518 has a substantially hexagonal cross-sectional configuration, and asecond substantially X-shaped recessed section 528 is internally formedat an axially central location within the hexagonally configured drivemember 518 so as to define a Phillips head drive member. It is furthernoted that the upper surface portion 516 of the centrally locatedhexagonally configured drive member 518, which is disposed substantiallytransversely or perpendicular to the longitudinal axis of the threadedscrew fastener 510, has a domed configuration, similar to the uppersurface portions 316,416 of the threaded screw fasteners 310, 410, suchthat the upper surface portion 516 slopes downwardly in acircumferential manner from the axially located substantially X-shapedrecessed section 528 toward the six vertically or axially orientedexternal sides or facets 520 which effectively form the outer peripheryof the hexagonally configured drive member 518. However, as can bereadily appreciated from FIG. 7 in connection with the disclosure of thethird embodiment threaded screw fastener 510, particularly when comparedto FIGS. 5 and 6 and their respective disclosures of the first andsecond embodiment threaded screw fasteners 310, 410, it is noted that inlieu of the domed upper surface portion 516 effectively having a limitedradial or diametrical extent which is somewhat less than that of thecircular washer member 513, as was the case of the domed upper surfaceportion 316 of the first embodiment threaded screw fastener 310 ascompared to the radial or diametrical extent of the circular washermember 313, the domed upper surface portion 516 of the third embodimentthreaded screw fastener 510 has a radial or diametrical extent which issubstantially the same as that of the circular washer member 513.

In connection with such structure, it is therefore additionallyappreciated that in lieu of the vertically or axially oriented externalsides or facets 520 of the drive member 518 being defined within theperipheral surface of the circular washer member 513, as was the casewith the vertically or axially oriented external sides or facets 420with respect to the outer peripheral surface of the circular washermember 413, the vertically or axially oriented external sides or facets520 of the drive member 518 are disposed atop the circular washer member513 and are disposed slightly radially inwardly offset from the outerperipheral edge portion of the circular washer member 513. Stillfurther, it is also noted that the corner regions 526, defined betweenadjacent ones of the vertically or axially oriented external facets orsides 520 of the drive member 518 are effectively disposed at theperipheral edge of and within the plane of the circular washer member513. Accordingly, the vertical height dimension of the hexagonallyconfigured drive member 518, as defined by means of the axial extent ofthe six vertically or axially oriented external facets or sides 520 ofthe hexagonally configured drive member 518, is relatively small. Inaddition, as was characteristic of the head portions 314,414 of thefirst and second embodiment threaded screw fasteners 310,410, due to thecircumferentially extending, downwardly sloped contour of the uppersurface portion 516 of the hexagonally configured drive member 518, theupper edge portions 522 of the six vertically or axially orientedexternal sides or facets 520 of the hexagonally configured drive member518 are not disposed at the uppermost elevational level of the threadedscrew fastener 510.

Furthermore, since the upper surface portion 516 of the hexagonallyconfigured drive member 518 slopes downwardly in the aforenotedcircumferential manner, the upper edge regions 522 of the hexagonallyconfigured drive member 518, as defined at the junctions of the uppersurface portion 516 and each one of the external sides or facets 520 ofthe hexagonally configured drive member 518, do not comprise 90° angles.Still further, and again due to the circumferentially extending,downwardly sloped contour of the upper surface portion 516 of thehexagonally configured drive member 518, and in particular, due to thedisposition of the corner regions 526, as defined between adjacent onesof the vertically or axially oriented external facets or sides 520 ofthe drive member 518, within the plane of the circular washer member513, the presence of such sharply cornered regions, at a relatively highelevational level upon the head portion 514 of the threaded screwfastener 510, has effectively been eliminated. Accordingly, if portionsof the waterproof or environmental membranes happen to be effectivelyforced into con-tact with the head portions 514 of the threaded screwfasteners 510 that secure the waterproof or environmental membranes tothe underlying roof decking assembly, as a result of, for example,workmen personnel walking upon the upper surface portion of the roofdecking assembly, then the waterproof or environmental membranes will beforced into contact with and thereby encounter the circumferentiallyextending, downwardly sloped upper surface portions 516 of the threadedscrew fasteners 510, and will not be forced into contact with orencounter any sharply pointed edge or corner regions of the sixvertically or axially oriented external sides or facets of thehexagonally configured drive member 518. Therefore, cutting, piercing,and ultimate shredding or tearing of the waterproof or environmentalmembranes is effectively prevented.

Still further, it is also to be appreciated that by means of providingthe third embodiment threaded screw fastener 510 with the combinationfastener drive structure 518, 528 that permits the third embodimentthreaded screw fastener 510 to be rotatably driven by means ofalternative drive socket implements or tools, such as, for example,hexagonally configured socket implements or tools, or by means ofPhillips head configured socket implements or tools, only a single typeof threaded screw fastener 510 is needed at field installation or jobsite locations. This mode of operation is of course facilitated orenabled in view of the fact that the single type of threaded screwfastener 510 can be inserted or installed within a substrate regardlessof the type of drive socket implement or tool that a particular workmanor field personnel may be using at the field installation or job site.

With reference now being made to FIGS. 8 and 9, a new and improved drivesocket implement or tool, for operatively engaging the head portion ofany one of the threaded screw fasteners 310,410,510, as disclosed withinFIGS. 5-7, so as to impart a rotatable drive force thereto, is disclosedand is generally indicated by the reference character 610. As can bereadily appreciated, the new and improved drive socket implement or tool610 is seen to comprise a cylindrical housing 612 which is open at thefront end thereof so as to define a socket member 614 therewithin foraccommodating and operatively mating with at least some of the drivestructure defined upon the head portion of any one of the aforenotedthreaded screw fasteners 310,410,510. It is to be noted that while, forexample, the new and improved drive socket implement or tool 610 isdisclosed as being operatively engaged with the head portion 314 of thethreaded screw fastener 310, the new and improved drive socket implementor tool 610 can be structurally configured so as to appropriatelyoperatively engage the head portions 414,514 of the threaded screwfasteners 410,510. More particularly, it is seen that the socket member614 of the new and improved drive socket implement or tool 610 isprovided with an annular or peripheral front face 616 which is disposedwithin a plane that is substantially perpendicular to the longitudinalaxis of the socket implement or tool 610. Six inner peripheral wallmembers 618 of the socket member 614 are disposed within the immediatevicinity of the front face 616 of the socket implement or tool 610 so asto extend axially rearwardly from the front face 616 of the socketimplement or tool 610, and in addition, the six inner peripheral wallmembers 618 are disposed within a circumferential array so as toeffectively circumscribe a region within the socket member 614 which hasa substantially hexagonal configuration. In this manner, when the newand improved socket implement or tool 610 is operatively engaged withthe head portion 314 of the threaded screw fastener 310, the sides orfacets 320 of the hexagonally configured drive member 318 can bedrivingly engaged by means of the hexagonally arranged wall members 618of the socket member 614. At the same time, it can likewise beappreciated that the front face 616 of the socket member 614 is properlyseated upon the upper surface portion of the circular washer member 313,as can best be appreciated from FIG. 9, whereby the longitudinal axes ofthe socket implement or tool 610 and the threaded screw fastener 310 arecoaxially aligned with respect to each other.

Continuing still further, it is appreciated that the socket member 614is also provided with an axially located, forwardly extending,substantially X-shaped conical projection 620 which effectively definesa Phillips head screwdriver element which is adapted to operativelyengage the X-shaped Phillips head recessed portion 328 defined withinthe head portion 314 of the threaded screw fastener 310 when, forexample, the socket implement or tool 610 is operatively engaged withthe head portion 314 of the threaded screw fastener 310 as disclosedwithin FIG. 9. Accordingly, the Phillips head screwdriver element 620can be operatively used to engage the X-shaped Phillips head recessedportion 328 defined within the head portion 314 of the threaded screwfastener 310 in conjunction with the operative or driving engagement ofthe sides or facets 320 of the hexagonally configured drive member 318of the head portion 314 of the threaded screw fastener 310 by means ofthe hexagonally arranged wall members 618 of the socket member 614.Lastly, in connection with the internal structure comprising the socketmember 614, it is also seen that the socket member 614 comprises aconcavely contoured mating surface 622 which is adapted to house oraccommodate, for example, the domed upper surface portion 316 of thehead portion 314 of the threaded screw fastener 310.

It is to be noted that while the socket member 614 may be provided withboth the hexagonal drive means comprising the plurality of side wallmembers 618, as well as the Phillips head screwdriver element 620, inconjunction with the contoured mating surface 622, so as to properlydrivingly engage the head portion 314 of the threaded screw fastener310, only a single one of the drive means 618,620 truly needs to beprovided in view of the fact that the threaded screw fastener 310 isprovided with the dual drivable means 320, 328. On the other hand, it isfurther noted that just as the dual drivable means 320,328 as providedupon the threaded screw fastener 310, permits the same to be drivinglyused and engaged by means of any drive socket implement or tool, theprovision of the dual driving means 618,620, upon the socket implementor tool 610, permits it to drivingly engage any particular threadedscrew fastener. It is lastly noted that in order to provide the socketimplement or tool 610 with rotary drive motion to be appropriate oraccordingly transmitted to the threaded screw fastener 310, it is seenthat the housing 612 is mounted upon the forward end of a shaft member624, and that the rear end of the shaft member 624 is provided with astem portion 626 for insertion within, for example, a suitable colletmember, not shown, of a rotary drive tool, also not shown.

With reference now being made to FIGS. 10 and 11, a fourth embodiment ofa new and improved threaded screw fastener constructed in accordancewith the teachings and principles of the present invention is disclosedand is generally indicated by the reference character 710. As disclosedwithin FIGS. 10 and 11, the new and improved threaded screw fastener 710comprises a shank portion 712 and a buttress thread portion 714,however, if the new and improved threaded screw fastener 710, asdisclosed within FIGS. 10 and 11, is compared to the conventional PRIORART threaded screw fastener 210 as disclosed within FIGS. 3 and 4, itwill be readily apparent that the structure of the individual threads714 of the threaded screw fastener 710, as constructed in accordancewith the principles and teachings of the present invention, is quitedifferent from the structure of the individual threads 214 of theconventional PRIOR ART threaded screw fastener 210. More particularly,it is seen that in lieu of the conventional, PRIOR ART threaded screwfastener 210, wherein the individual threads 214 comprise, in effect, aslightly inclined rearward planar flank surface 216, and a significantlyinclined forward planar flank surface 218, the individual threads 714 ofthe threaded screw fastener 710 of the present invention comprise atleast one, and preferably two, substantially perpendicular rearwardplanar flank surfaces 716-1,716-2, and dual, inclined forward planarflank surfaces 718-1,718-2.

It is to be noted that, in connection with the structural design of thescrew threads upon threaded screw fasteners, and as is well-known in theart or industry, as has been discussed hereinbefore, the rearward flanksurface structure of each individual thread, as well as the pitchdefined between each pair of adjacent threads, play critical roles in,or effectively determine, the pull-out resistance characteristics orproperties of the threaded screw fastener, while the forward flanksurface structure of each individual thread, as well as the spacingdefined between the root portion of the rearward flank surface of aparticular thread and the root portion of the forward flank surface ofan adjacent thread, likewise play critical roles in, or effectivelydetermine, the installation or insertion torque characteristics orproperties of the threaded screw fastener. In particular, for example,as the perpendicularity of the rearward flank surface of each individualthread with respect to the longitudinal axis of the threaded screwfastener is increased, then the pull-out resistance characteristics orproperties of the threaded screw fastener are likewise or accordinglyincreased, whereas as the inclination of the forward flank surface ofeach individual thread with respect to the radius of the threaded screwfastener is decreased, then the insertion or installation torquecharacteristics or properties are accordingly or likewise decreased. Inconjunction with the particularly fabricated structure of the rearwardand forward flank surfaces of the individual threads, it is also notedthat the aforenoted pitch and spacing dimensions will be accordinglyvaried in order to likewise affect the pull-out resistance andinstallation or insertion torque characteristics or properties of thethreaded screw fastener.

With reference therefore being made more specifically to FIG. 11, thelongitudinal axis of the threaded screw fastener 710 is disclosed at722, while a radius of the threaded screw fastener 710 is disclosed at724. Accordingly, it can be appreciated that the angular extent orinclination of the radially outer forward flank surface 718-1 withrespect to the radius 724 is designated by means of the angle A1, whilethe angular extent or inclination of the radially inner forward flanksurface 718-2 with respect to the radius 724 is designated by means ofthe angle A2. In a similar manner, the angular extent or inclination ofthe radially outer rearward flank surface 716-1 with respect to theradius 724 is designated by means of the angle A3, while the angularextent or inclination of the radially inner rearward flank surface 716-2with respect to the radially outer rearward flank surface 716-1 isdesignated by means of the angle A4. Still further, the axial extent orlength of the crest portion 720 of each thread 714 is denoted by meansof the linear dimension D1, while the radial extent or width of eachthread 714 is denoted by means of the linear dimension D2, the radialextent or width of the radially inner rearward flank surface 716-2 ofeach thread 714 is denoted by means of the linear dimension D3, and theaxial extent or distance defined between the root portion of therearward flank surface of a particular thread 714 and the root portionof the forward flank surface of an adjacent thread 714 is denoted bymeans of the linear space dimension D4. In a similar manner, the radialextent or width of the radially inner forward flank surface 718-2 ofeach thread 714 is denoted by means of the linear dimension D5, theradial extent or width of the radially outer forward flank surface 718-1of each thread 714 is denoted by means of the linear dimension D6, andthe axial extent or distance defined between each pair of adjacentthreads 714,714 is denoted by means of the linear pitch dimension D7.

Continuing further with reference being made to FIG. 11, and inaccordance with the unique and novel teachings and principles of thepresent invention, due to the provision of, for example, the radiallyinner forward flank surface 718-2, wherein the same is disposed at theangular inclination A2, which is relatively steeper than the angularinclination A1 at which the radially outer forward flank surface 718-1is disposed with respect to the radius 724, that is, the radially innerforward flank surface 718-2 is disposed so as to be more perpendicularwith respect to the longitudinal axis 722 of the threaded screw fastener710 than is the radially outer forward flank surface 718-1, then it canbe appreciated that a portion of the forward flank surface, as denotedin phantom lines at 718-3, has in effect been removed when compared, forexample, to the forward flank surface 218 of the standard buttressthread 210 as disclosed within FIG. 4. Accordingly, since less materialis effectively present upon each composite forward flank surface718-1,718-2 of each thread 714, less material is effectively present inorder to operatively engage the material comprising the substrate intowhich the threaded screw fastener 710 is being inserted. In this manner,the provision of the particularly structured radially inner forwardflank surface 718-2 upon each thread 714 effectively reduces theinstallation or insertion torque characteristics or properties of thethreaded screw fastener 710.

In a corresponding manner, the provision of the particularly structuredradially inner forward flank surface 718-2 upon each thread 714, and theparticular angular inclinations A1,A2 of the radially outer forwardflank surface 718-1 and the radially inner forward flank surface 718-2upon each thread 714, effectively affect or alter the axial extent ordistance dimension D4 as defined between the root portion of therearward flank surface of a particular thread 714 and the root portionof the forward flank surface of an adjacent thread 714. These factorscorrespondingly affect the installation torque characteristics orproperties of the threaded screw fastener 710 in that as the axialextent or distance dimension D4 is effectively increased, an increasedamount of room or space is effectively provided in order to accommodatethe material, comprising the substrate into which the threaded screwfastener 710 is being installed or inserted, thereby effectivelyreducing the installation or insertion torque characteristics orproperties of the threaded screw fastener 710. It will also beappreciated that as the angular inclinations A1,A2 of the radially outerforward flank surface 718-1 and the radially inner forward flank surface718-2 of each thread 714 are respectively varied, the radial extentsD6,D5 of the radially outer forward flank surface 718-1 and the radiallyinner forward flank surface 718-2 of each thread 714 will likewise bevaried. Again, all of these factors effectively influence the amount ofmaterial which is effectively present upon the threads 714 of thethreaded screw fastener 710 for operatively engaging the materialcomprising the substrate into which the threaded screw fastener 710 isbeing inserted.

Continuing still further, and in accordance with additionally unique andnovel teachings and principles of the present invention, it is seen thatthe radially inner rearward flank surface 716-2 is disposed at theangular inclination A4 with respect to the radially outer rearward flanksurface 716-1, and that the radially outer rearward flank surface 716-1is disposed at the angular inclination A3 with respect to the radius724. As a result of this structural relationship, it is further seenthat the radially inner rearward flank surface 716-2 is disposed so asto be more perpendicular with respect to the longitudinal axis 722 ofthe threaded screw fastener 710 than is the radially outer rearwardflank surface 716-1. Since the degree of perpendicularity of therearward flank surfaces of the threads of a threaded screw fastener issignificantly determinative of the pull-out resistance characteristicsor properties of the threaded screw fastener, it can be appreciated thatby providing the radially inner rearward flank surface 716-2 as adistinctly separate planar surface with respect to or separate from theradially outer rearward flank surface 716-1, and wherein, for example,the radially inner rearward flank surface 716-2 can be disposedsubstantially perpendicular to the longitudinal axis 722 of the threadedscrew fastener 710 while the radially outer rearward flank surface 716-1is disposed at some predetermined angle, other than 90° with respect tothe longitudinal axis 722 of the threaded screw fastener 710, thenenhanced pull-out resistance characteristics or properties of thethreaded screw fastener 710 can be achieved.

It is also noted in conjunction with the foregoing that by altering theradial extent or width dimension D3 of the radially inner rearward flanksurface 716-2, the pull-out resistance characteristics or properties ofthe threaded screw fastener 710 can likewise be adjusted or altered. Forexample, as the radial extent or width dimension D3 of the radiallyinner rearward flank surface 716-2 is increased, the pull-out resistancecharacteristics or properties of the threaded screw fastener 710 willlikewise be increased. Similar pull-out resistance characteristics orproperties of the threaded screw fastener 710 can also be achieved bycorrespondingly altering the radial extent or width dimension D2 of thethreads 714, as defined between the root portions 726 of the threads 714and the crest portions 720 of the threads 714. In particular, byincreasing the radial extent or width dimension D2 of the threads 714,the pull-out resistance characteristics or properties of the threadedscrew fastener 710 will likewise be increased. In a still similarmanner, the pull-out resistance characteristics or properties of thethreaded screw fastener 710 can also be achieved by altering the axialextent or distance defined between identical points defined upon eachpair of adjacent threads 714,714 as denoted by means of the linear pitchdimension D7. More particularly, as the linear pitch dimension D7 isdecreased, whereby an increased number of threads 714 per axial inch iseffectively achieved, the pull-out resistance characteristics orproperties of the threaded screw fastener 710 are correspondinglyincreased.

It is to be noted still further that while the separate planar radiallyouter and radially inner rearward flank surfaces 716-1,716-2 have beendisclosed and discussed, it is not necessary to in fact provide suchseparate planar rearward flank surfaces in order to achieve the desiredpull-out resistance characteristics or properties for the threaded screwfastener 710. More particularly, since the degree of perpendicularity ofthe rearward flank surfaces of the threads of the threaded screwfastener is significantly determinative of the pull-out resistancecharacteristics or properties of the threaded screw fastener, theseparate planar radially outer and radially inner rearward flanksurfaces 716-1,716-2 can in effect be coplanar as a result, for example,where the angular inclination A4, as defined between the separate planarradially outer and radially inner rearward flank surfaces 716-1,716-2,is effectively 0°. In this manner, the separate planar radially outerand radially inner rearward flank surfaces 716-1,716-2 effectivelybecome a single planar rearward flank surface. This single planarrearward flank surface of the threaded screw fastener 710 of the presentinvention is noted as being significantly different from theconventional PRIOR ART planar rearward flank surface 216 of the threadedscrew fastener 210 in that the angular inclination A3 of such singleplanar rearward flank surface of the threaded screw fastener 710 of thepresent invention is such as to dispose the single planar rearward flanksurface of the threaded screw fastener 710 of the present invention atan orientation which is substantially more perpendicular than thatcharacteristic of the conventional PRIOR ART planar rearward flanksurface 216 of the threaded screw fastener 210. In particular, forexample, the conventional PRIOR ART planar rearward flank surface 216 ofeach threaded screw fastener 210 is disposed at an angular inclinationwhich is within the range of 8-10°. However, in accordance with theprinciples and teachings of the present invention, the single planarrearward flank surface of the threaded screw fastener 710 of the presentinvention is disposed at an angle which is within the range of 0-7°,with the preferred angular inclination being 5°.

It is lastly to be noted that while the unique and novel teachings ofthe present invention can be applied to various conventionally sizedthreaded screw fasteners, the following chart illustrates the variousexemplary flank surface angles A1,A2,A3,A4, as well as the variousradial and axial linear dimensions D1,D2,D3,D4,D5,D6,D7, that have beendeveloped in connection with a Number 15 threaded screw fastener. Itwill of course be appreciated that the various angles and lineardimensions may therefore vary depending upon the size of the particularthreaded screw fastener.

Example—A Number 15 Sized Threaded Screw Fastener Angle of RadiallyOuter A1 - 20-40° Forward Flank Surface Angle of Radially Inner A2 0-35° Forward Flank Surface Angle of Radially Outer A3 0-7° RearwardFlank Surface Angle of Radially Inner A4 0-7° Rearward Flank SurfaceAxial Length of Thread D1 0.005-0.015 inches Crest Portions Radial orWidth Extent D2 0.04-0.09 inches of Fasteners Threads Radial or WidthExtent D3 0.00-0.09 inches of Radially Inner Rearward Flank SurfaceAxial Spacing Defined D4 0.01-0.03 inches Between Root Portions ofAdjacent Threads Radial or Width Extent D5 0.00-0.09 inches of RadiallyInner Forward Flank Surface Radial or Width Extent D6 0.00-0.09 inchesof Radially Outer Forward Flank Surface Axial Length or Pitch D70.067-0.091 inches Dimension Defined Between Identical Locations ofAdjacent Threads

With reference now being made to FIGS. 12 and 13, another new andimproved threaded screw fastener, specifically constructed in accordancewith the principles and teachings of the present invention for use inconnection with the securing together of overlapped edge portions ofadjacent roofing panels such that the new and improved threaded screwfasteners will not experience back-out from their secured positions orsites at which the overlapped edge portions of the adjacent roofingpanels are secured together, even when the roofing panels undergoexpansion and contraction under varying weather and temperatureconditions, is disclosed and is generally indicated by the referencecharacter 810. Firstly, with respect to the overall structure comprisingthe new and improved threaded screw fastener 810, it is noted that thethreaded screw fastener 810 comprises a shank portion 812, a head member814 formed upon a first end portion of the shank portion 812, and a tipmember 816 formed upon a second opposite end portion of the shankportion 812. The tip member 816 is provided with at least one recessedregion 818 upon a side wall portion thereof so as to provide thethreaded screw fastener 810 with either a self-drilling or gimlet point.

In addition, it is seen that the head member 814 comprises an axially orcentrally located recessed portion 820, for accommodating a drive toolby means of which rotary torque may be impressed upon the threaded screwfastener 810 in order to install the same within a substrate, and anannular flanged or shoulder portion 822 which is provided with anannular recessed portion 824 upon the undersurface portion or sidethereof for accommodating a sealing washer, not shown, fabricated fromrubber or other similar material. Accordingly, when the threaded screwfastener 810 is inserted into, and fully tightened within, aperturesformed within overlapped edge portions of adjacent roofing panels to besecured together, the rubber or similar material sealing washer willseal tightly against the location or site, at which the threaded screwfastener 810 has been inserted through the apertures formed within theoverlapped edge portions of adjacent roofing panels, so as to ensuresealing of the location or site against the incursion or penetration ofwater.

Continuing further, and with particular reference now being made to FIG.13, the external surface portion of the shank portion 812 of thethreaded screw fastener 810 is provided with an annular buttress thread826 which is specifically structured so as to prevent back-out of thethreaded screw fastener 810 with respect to the overlapped edge portionsof the roofing panels whereby the sealed integrity of the fastener siteswill be preserved. More particularly, as has been noted hereinbefore,roofing systems are subjected to environmental and weather conditionswhich cause the roofing panels to undergo cyclical expansion andcontraction, and as a result of such cyclical expansion and contractionof the roofing panels, forces are impressed upon the threaded fastenersthat cause them to become loose and back out from their fastened statesor positions within the overlapped edge portions of the adjacent roofingpanels. Accordingly, at this point in time, the rubber washers, or thelike, will no longer be engaged with the overlapped edge portions ofadjacent roofing panels whereby, in turn, the fastener sites will nolonger be properly sealed or protected against water incursion orpenetration. In accordance with the principles and teachings of thepresent invention, the new and improved threaded screw fastener 810comprises the new and improved buttress thread form 826 upon theexternal surface portion thereof such that the threaded fasteners 810will not in fact become loose and back out from their fastened states orpositions within the overlapped edge portions of the adjacent roofingpanels. As can be seen from FIG. 13, the new and improved buttressthread form 826 is seen to comprise a thread form which is somewhatsimilar to that defined by means of the conventional threads 214 formedupon the conventional, PRIOR ART fastener 210 as disclosed within FIG.4, however, if the new and improved thread form 826 of the new andimproved threaded screw fastener 810, as disclosed within FIG. 13, iscompared to the conventional PRIOR ART threaded screw fastener 210 asdisclosed within FIG. 4, it will be readily apparent that the structureof the individual threads 828 comprising the thread form 826 of thethreaded screw fastener 810, as constructed in accordance with theprinciples and teachings of the present invention, are quite differentfrom the structure of the individual threads 214 of the conventionalPRIOR ART threaded screw fastener 210.

More particularly, it is seen that in lieu of the conventional, PRIORART threaded screw fastener 210, wherein the individual threads 214comprise, in effect, a slightly inclined rearward planar flank surface216, and a significantly inclined forward planar flank surface 218,wherein the spacing S, as defined between the root portions of anadjacent forward flank surface 218 and an adjacent rearward flanksurface 216, is relatively small, the individual threads 828 of thethread form 826 of the threaded screw fastener 810 of the presentinvention comprise a substantially perpendicular rearward planar flanksurfaces 830, and an inclined, forward planar flank surface 832. As hasbeen noted hereinbefore, and as is well-known in the industry inconnection with the structural design or formation of the screw threadsupon threaded screw fasteners, the rearward flank surface structure ofeach individual thread, as well as the pitch defined between each pairof adjacent threads, play important roles in, or effectively determine,the pull-out resistance characteristics or properties of the threadedscrew fastener.

In a similar manner, the forward flank surface structure of eachindividual thread, as well as the spacing defined between the rootportion of the rearward flank surface of a particular thread and theroot portion of the forward flank surface of an adjacent thread,likewise play important roles in, or effectively determine, theinstallation or insertion torque characteristics or properties of thethreaded screw fastener. In particular, for example, as theperpendicularity of the rearward flank surface of each individual threadwith respect to the longitudinal axis of the threaded screw fastener isincreased, then the pull-out resistance characteristics or properties ofthe threaded screw fastener are likewise or accordingly increased,whereas as the inclination of the forward flank surface of eachindividual thread with respect to the radius of the threaded screwfastener is decreased, then the insertion or installation torquecharacteristics or properties are accordingly or likewise decreased. Inconjunction with the particularly fabricated structure of the rearwardand forward flank surfaces of the individual threads, it is also notedthat the aforenoted pitch and spacing dimensions may accordingly bevaried in order to likewise affect the pull-out resistance andinstallation or insertion torque characteristics or properties of thethreaded screw fastener.

With reference therefore being made to FIGS. 12 and 13, the longitudinalaxis of the threaded screw fastener 810 is disclosed at 834, while aradius of the threaded screw fastener 810 is disclosed at 836.Accordingly, it can be appreciated that the angular extent orinclination of the inclined, forward planar flank surface 832 withrespect to the radius 836 is designated by means of the angle B1, whilethe angular extent or inclination of the rearward planar flank surface830 with respect to the radius 836 is designated by means of the angleB2. Still further, the axial extent or length of the crest portion 838of each thread 828 is denoted by means of the linear dimension L1, theradial extent or width of each one of the threads 828, as definedbetween the root portion 837 of the thread 828 and the crest portion 838of the thread 828, is denoted by means of the linear dimension L2, theaxial extent or distance defined between each pair of adjacent threads828,828 is denoted by means of the linear pitch dimension L3, and theaxial extent or distance defined between the root portion of therearward planar flank surface of a particular thread 828 and the rootportion of the inclined planar forward flank surface of an adjacentthread 828 is denoted by means of the linear space dimension L4. Moreparticularly, the axial extent or length dimension L1 of the crestportion 838 of each one of the threads 828 is preferably 0.005 inches,the radial extent or width dimension L2 of each one of the threads 828may be within the range of 0.010-0.085 inches, and the axial extent,distance, or pitch dimension L3 defined between each pair of adjacentthreads 828,828 may be within the range of 0.035-0.090 inches.

Continuing further, the axial extent or distance dimension L4 definedbetween the root portion of the rearward planar flank surface of aparticular thread 828 and the root portion of the inclined planarforward flank surface of an adjacent thread 828 may be within the rangeof 0.035-0.090 inches. The reason for this is that each one of theroofing panels is fabricated, for example, from 24 gauge metal stockwherein each roofing panel therefore has a thickness dimension of, forexample, 0.024 inches. Accordingly, after each one of the threaded screwfasteners 810 has been inserted through the overlapped edge portions ofthe adjacent roofing panels, the overlapped edge portions 840,842 of theadjacent roofing panels will in fact be able to be tightly accommodatedwithin the space defined between the root portion of the rearward planarflank surface of a particular thread 828 and the root portion of theinclined planar forward flank surface of an adjacent thread 828, thatis, the space having the axial extent or distance dimension L4. It cantherefore be appreciated that the overlapped edge portions of theroofing panels will effectively be trapped between the surfacecomprising one of the rearward planar flank surfaces 830 and the rootportion of the adjacent inclined forward planar flank surface 832. It isof course to be appreciated further that depending upon the gaugethickness or dimension of the metal material from which the roofingpanels are fabricated, then the space having the axial extent ordistance dimension L4 may accordingly be altered so as to effectivelymatch or accommodate the gauge thickness of the metal material used tofabricate the roofing panels. In this manner, the overlapped edgeportions of the roofing panels will always be substantially tightlydisposed or effectively within the space defined between the surfacecomprising one of the rearward planar flank surfaces 830 and the rootportion of the adjacent inclined forward planar flank surface 832 andhaving the axial extent or distance dimension L4 such that the threadedscrew fastener 810 will exhibit good back-out resistance even afterbeing subjected to cyclical weather conditions which cause the roofingpanels to undergo expansion and contraction. Along these lines, it isnoted, for example, that the roofing panels may comprise overlapped 24or 26 gauge panels with sealer tape interposed therebetween so as toeffectively seal the overlapped seam defined between the pair ofoverlapped edge portions of the roofing panels, or alternatively 22 or24 gauge panels with sealer tape interposed therebetween so as toeffectively seal the overlapped seam defined between the pair ofoverlapped edge portions of the roofing panels. The roofing panels mayalso have pre-drilled pilot holes defined therein, and lastly, theroofing panels may be adapted for connection to, for example, 14 gaugeroofing purlins that may be solid or may be provided with pre-drilledholes.

It is to be noted further that while, for example, the angle B1 at whichthe inclined forward planar flank surface 832 extends with respect tothe radius 836 may be within the range of, for example, 0°-60°, such anangle may be altered so as to, in turn, alter the torque insertion andpull-out resistance characteristics of the threaded screw fastener 810,however, the thread rolling process is facilitated or enabled by meansof such an angle B1. In fact, a variation of the threaded screw fastener810 is disclosed within FIG. 14, as generally indicated by the referencecharacter 910, wherein it is to be appreciated that the variouscomponents of the threaded screw fastener 910, which correspond to thevarious components of the threaded screw fastener 810, will bedesignated by similar reference numbers except that they will be withinthe 900 series, and wherein it is seen that the angle B1 has effectivelybecome 0° so that the forward planar flank surface 932 will now bedisposed substantially parallel to the rearward planar flank surface 930which is also disposed, for example, at an angle B2 of 0°. In addition,the axial extent or distance dimension L4, as well as the thread pitchaxial extent or distance L3, will likewise be altered so as to stilleffectively substantially tightly accommodate the overlapped edgeportions 940,942 of the roofing panels therebetween. While such athreaded screw fastener 910 may therefore exhibit good pull-out andback-out resistance properties, it is somewhat more difficult tomanufacture and the torque insertion levels may be substantiallyincreased. This may similarly be the case if the radial extent or widthdimension L2 of the threads 826, as defined between the root portions837 of the threads 826 and the crest portions 838 of the threads 826, isaltered, that is, increased.

In particular, by increasing the radial extent or width dimension L2 ofthe threads 828, the pull-out resistance characteristics or propertiesof the threaded screw fastener 810 will be increased however torqueinsertion levels will also be increased. In a still similar manner,particular pull-out resistance characteristics or properties of thethreaded screw fastener 810 can also be achieved by altering the axialextent or distance defined between identical points defined upon eachpair of adjacent threads 828,828 as denoted by means of the linear pitchdimension L3. More particularly, as the linear pitch dimension L3 isdecreased, whereby an increased number of threads 828 per axial inch iseffectively achieved, the pull-out resistance characteristics orproperties of the threaded screw fastener 810 are correspondinglyincreased, however, torque insertion is also increased. It is notedstill further that while the angle B2 is within the range of 0°-6°, itis not desirable to dispose the rearward planar flank surface 830 of thethread 828 at any substantially larger angle because then the rearwardplanar flank surface 830 will not be able to effectively orsubstantially define surface-to-surface contact with the entrappedoverlapped edge portions of the roofing panels.

It is lastly to be noted that while the unique and novel teachings ofthe present invention can be applied to various conventionally sizedthreaded screw fasteners, the following chart illustrates the variousexemplary flank surface angles B1,B2, as well as the various radial andaxial linear dimensions L1,L2,L3,L4, that have been developed inconnection with a Number 10 threaded screw fastener which is to be usedin connection with 24 gauge roofing panels. It will of course beappreciated that the various angles and linear dimensions may thereforevary depending upon the size of the particular threaded screw fastener.

Example—A Number 10 Sized Threaded Screw Fastener Angle of Forward B1 0-60° Flank Surface Angle of Rearward B2 0-6° Flank Surface AxialLength of Thread L1 0.005 inches Crest Portions Radial or Width ExtentL2 0.010-0.085 inches of Fasteners Threads Axial Length or PitchDimension L3 0.035-0.090 inches Defined Between Identical Locations OfAdjacent Threads Axial Spacing Defined L4 0.035-0.090 inches BetweenRoot Portions of Adjacent Threads

Thus, it may be seen that in accordance with the principles andteachings of the present invention, there has been provided a new andimproved threaded screw fastener which is provided with a head portionthat has integrally incorporated therein unique and novel combination ordual drive means whereby the single threaded screw fastener can berotatably driven by means of alternative rotary drive socket implementsor tools, such as, for example, hexagonally configured or Phillips headconfigured drive means, or a combination drive tool. In this manner, thethreaded screw fastener, having such combination head structure, can bedrivingly inserted or installed within substrates regardless of theparticular drive socket implement or tool being utilized by fieldinstallation or job site personnel. Furthermore, there is provided a newand improved drive socket implement or tool which has integrallyincorporated therein both hexagonally configured drive structure,Phillips head drive structure, and domed contour structure for not onlystructurally accommodating both the hexagonally configured structure andthe Phillips head structure integrally incorporated upon the headportion of the threaded screw fastener, but in addition, foraccommodating the low profile domed structure of the head portion of thethreaded screw fastener. Still further, the threaded screw fastener alsocomprises thread structure wherein each thread of the threaded screwfastener comprises unique and novel rearward and forward flank surfaceswhich effectively serve to simultaneously enhance the pull-outresistance characteristics or properties of the threaded screw fastenerwhile reducing the installation or insertion torque characteristics orproperties of the threaded screw fastener. Lastly, the threaded screwfastener has unique structure that permits the same to be used inconnection with the seaming together of overlapped edge portions ofadjacent roofing panels.

Obviously, many variations and modifications of the present inventionare possible in light of the above teachings. For example, it is to benoted that not all of the unique and novel head drive and threadfeatures, as have been disclosed as being characteristic of the presentinvention, are necessarily included within a single threaded fastener,or within a single socket implement or tool. In addition, while thedrive structure incorporated within the head portion of the threadedscrew fastener, as well as the corresponding structure incorporatedwithin the drive socket implement or tool, has been primarily disclosedas comprising the hexagonal and Phillips head drive structure, it isnoted that other drive combinations are possible. For example, in lieuof the Phillips head drive structure, other drive structure, selectedfrom the group comprising Torx drive means, six-lobe drive means,internal hex drive means, and square drive means, may likewise beemployed in accordance with the principles and teachings of the presentinvention. It is therefore to be understood that within the scope of theappended claims, the present invention may be practiced otherwise thanas specifically described herein.

1. A threaded screw fastener, adapted to be used in connection with thesecuring together of overlapped edge portions of roofing panels havingpredetermined thickness dimensions, so as to securely fasten saidthreaded screw fastener at its threadedly secured position within theoverlapped edge portions of the roofing panels, comprising: a shankportion defined around a longitudinal axis; a head portion formed uponone end of said shank portion; a tip portion formed upon an opposite endof said shank portion; and a plurality of threads disposed upon saidshank portion of said threaded screw fastener; wherein each one of saidplurality of threads disposed upon said shank portion of said threadedscrew fastener comprises a rearward flank surface portion and a forwardflank surface portion, and wherein adjacent threads are separated fromeach other a predetermined amount so as to define a space therebetween,as defined between the root portion of said forward flank surfaceportion of a particular one of said plurality of threads and the rootportion of said rearward flank surface portion of an adjacent successiveone of said plurality of threads, for securely accommodating theoverlapped edge portions of the roofing panels, fabricated frompredetermined gauge material having predetermined thickness dimensions,within said space defined between said adjacent threads.
 2. The threadedscrew fastener as set forth in claim 1, wherein: said space, definedbetween said root portions of said forward flank surface portion andsaid rearward flank surface portion of adjacent threads which areseparated from each other by means of said predetermined amount, has adimension of at least 0.035 inches so as to securely accommodate theoverlapped edge portions of roofing panels.
 3. The threaded screwfastener as set forth in claim 1, wherein: said space, defined betweensaid root portions of said forward flank surface portion and saidrearward flank surface portion of adjacent threads which are separatedfrom each other by means of said predetermined amount, has a dimensionwhich is within the range of 0.035-0.090 inches so as to securelyaccommodate the overlapped edge portions of roofing panels which arefabricated from 22-26 gauge material.
 4. The threaded screw fastener asset forth in claim 1, wherein: said forward flank portion of each one ofsaid plurality of threads is disposed at a first predetermined anglewith respect to a radius of said shank portion of said threaded screwfastener; and said rearward flank portion of each one of said pluralityof threads is disposed at a second predetermined angle with respect tosaid radius of said shank portion of said threaded screw fastener. 5.The threaded screw fastener as set forth in claim 4, wherein: saidsecond predetermined angle, at which said rearward flank portion of eachone of said plurality of threads is oriented with respect to said radiusof said shank portion of said threaded screw fastener, is substantiallyless than said first predetermined angle at which said forward flankportion of each one of said plurality of threads is oriented withrespect to said radius of said shank portion of said threaded screwfastener.
 6. The threaded screw fastener as set forth in claim 5,wherein: said first predetermined angle, at which said forward flankportion of each one of said plurality of threads is oriented withrespect to said radius of said shank portion of said threaded screwfastener, is within the range of 0°-60°; and said second predeterminedangle, at which said rearward flank portion of each one of saidplurality of threads is oriented with respect to said radius of saidshank portion of said threaded screw fastener, is within the range of0°-6°.
 7. The threaded screw fastener as set forth in claim 4, wherein:said first predetermined angle, at which said forward flank portion ofeach one of said plurality of threads is oriented with respect to saidradius of said shank portion of said threaded screw fastener, is withinthe range of 0°-60°; and said second predetermined angle, at which saidrearward flank portion of each one of said plurality of threads isoriented with respect to said radius of said shank portion of saidthreaded screw fastener, is within the range of 0°-6°.
 8. The threadedscrew fastener as set forth in claim 4, wherein: said firstpredetermined angle, at which said forward flank portion of each one ofsaid plurality of threads is oriented with respect to said radius ofsaid shank portion of said threaded screw fastener, is 0°; and saidsecond predetermined angle, at which said rearward flank portion of eachone of said plurality of threads is oriented with respect to said radiusof said shank portion of said threaded screw fastener, is 0°, wherebysaid forward flank portion of each one of said plurality of threads isdisposed substantially parallel to said rearward flank portion of eachone of said plurality of threads.
 9. The threaded screw fastener as setforth in claim 1, wherein: the radial extent of each one of saidplurality of threads, as defined between the root portion of the threadand the crest portion of the thread, is within the range of 0.010-0.085inches.
 10. In combination, a plurality of threaded screw fasteners,adapted to be used in connection with the securing together ofoverlapped edge portions of roofing panels having predeterminedthickness dimensions, comprising: a pair of overlapped edge portions ofadjacent roofing panels; and a plurality of threaded screw fastenersdisposed within said overlapped edge portions of said adjacent roofingpanels so as to fixedly secure said overlapped edge portions of saidadjacent roofing panels together in a seamed manner; each one of saidplurality of threaded screw fasteners comprising a shank portion definedaround a longitudinal axis; a head portion formed upon one end of saidshank portion; a tip portion formed upon an opposite end of said shankportion; and a plurality of threads disposed upon said shank portion ofsaid threaded screw fastener; wherein each one of said plurality ofthreads disposed upon said shank portion of said threaded screw fastenercomprises a rearward flank surface portion and a forward flank surfaceportion, and wherein adjacent threads are separated from each other apredetermined amount so as to define a space therebetween, as definedbetween the root portion of said forward flank surface portion of aparticular one of said plurality of threads and the root portion of saidrearward flank surface portion of an adjacent successive one of saidplurality of threads, for securely accommodating said overlapped edgeportions of said roofing panels, fabricated from predetermined gaugematerial having predetermined thickness dimensions, within said spacedefined between said adjacent threads.
 11. The combination as set forthin claim 10, wherein: said space, defined between said root portions ofsaid forward flank surface portion and said rearward flank surfaceportion of adjacent threads which are separated from each other by meansof said predetermined amount, has a dimension of at least 0.035 inchesso as to securely accommodate said overlapped edge portions of saidroofing panels.
 12. The combination as set forth in claim 10, wherein:said space, defined between said root portions of said forward flanksurface portion and said rearward flank surface portion of adjacentthreads which are separated from each other by means of saidpredetermined amount, has a dimension which is within the range of0.035-0.090 inches so as to securely accommodate said overlapped edgeportions of said roofing panels which are fabricated from 22-26 gaugematerial.
 13. The combination as set forth in claim 10, wherein: saidforward flank portion of each one of said plurality of threads isdisposed at a first predetermined angle with respect to a radius of saidshank portion of said threaded screw fastener; and said rearward flankportion of each one of said plurality of threads is disposed at a secondpredetermined angle with respect to said radius of said shank portion ofsaid threaded screw fastener.
 14. The combination as set forth in claim13, wherein: said second predetermined angle, at which said rearwardflank portion of each one of said plurality of threads is oriented withrespect to said radius of said shank portion of said threaded screwfastener, is substantially less than said first predetermined angle atwhich said forward flank portion of each one of said plurality ofthreads is oriented with respect to said radius of said shank portion ofsaid threaded screw fastener.
 15. The combination as set forth in claim14, wherein: said first predetermined angle, at which said forward flankportion of each one of said plurality of threads is oriented withrespect to said radius of said shank portion of said threaded screwfastener, is within the range of 0°-60°; and said second predeterminedangle, at which said rearward flank portion of each one of saidplurality of threads is oriented with respect to said radius of saidshank portion of said threaded screw fastener, is within the range of0°-6°.
 16. The combination as set forth in claim 13, wherein: said firstpredetermined angle, at which said forward flank portion of each one ofsaid plurality of threads is oriented with respect to said radius ofsaid shank portion of said threaded screw fastener, is within the rangeof 0°-60°; and said second predetermined angle, at which said rearwardflank portion of each one of said plurality of threads is oriented withrespect to said radius of said shank portion of said threaded screwfastener, is within the range of 0°-6°.
 17. The combination as set forthin claim 13, wherein: said first predetermined angle, at which saidforward flank portion of each one of said plurality of threads isoriented with respect to said radius of said shank portion of saidthreaded screw fastener, is 0°; and said second predetermined angle, atwhich said rearward flank portion of each one of said plurality ofthreads is oriented with respect to said radius of said shank portion ofsaid threaded screw fastener, is 0°, whereby said forward flank portionof each one of said plurality of threads is disposed substantiallyparallel to said rearward flank portion of each one of said plurality ofthreads.
 18. The combination as set forth in claim 10, wherein: theradial extent of each one of said plurality of threads, as definedbetween the root portion of the thread and the crest portion of thethread, is within the range of 0.010-0.085 inches.